Linus Carl Pauling (/ˈpɔːlɪŋ/; February 28, 1901 – August 19,
1994)[4] was an American chemist, biochemist, peace activist, author,
educator, and husband of American human rights activist Ava Helen
Pauling. He published more than 1,200 papers and books, of which about
850 dealt with scientific topics.[5]
New ScientistNew Scientist called him one of
the 20 greatest scientists of all time,[6] and as of 2000, he was
rated the 16th most important scientist in history.[7]
Pauling was one of the founders of the fields of quantum chemistry and
molecular biology.[8] His contributions to the theory of the chemical
bond include the concept of orbital hybridisation and the first
accurate scale of electronegativities of the elements. Pauling also
worked on the structures of biological molecules, and showed the
importance of the alpha helix and beta sheet in protein secondary
structure. Pauling's approach combined methods and results from X-ray
crystallography, molecular model building and quantum chemistry. His
discoveries inspired the work of
James WatsonJames Watson and
Francis CrickFrancis Crick on the
structure of DNA, which in turn made it possible for geneticists to
crack the DNA code of all organisms.[9]
In his later years he promoted nuclear disarmament, as well as
orthomolecular medicine, megavitamin therapy,[10] and dietary
supplements. None of the latter have gained much acceptance in the
mainstream scientific community.[6][11]
For his scientific work, Pauling was awarded the Nobel Prize in
Chemistry in 1954. For his peace activism, he was awarded the Nobel
Peace Prize in 1962. He is one of four individuals to have won more
than one Nobel Prize (the others being Marie Curie,
John BardeenJohn Bardeen and
Frederick Sanger).[12] Of these, he is the only person to have been
awarded two unshared Nobel Prizes,[13] and one of two people to be
awarded Nobel Prizes in different fields, the other being Marie
Curie.[12]

Pauling was born in Portland, Oregon,[14][15] the first-born child of
Herman Henry William Pauling (1876–1910) and Lucy Isabelle "Belle"
Darling (1881–1926).[16] He was named "Linus Carl", in honor of
Lucy's father, Linus, and Herman's father, Carl.[17]
In 1902, after his sister Pauline was born, Pauling's parents decided
to move out of Portland, to find more affordable and spacious living
quarters than their one-room apartment.[18] Lucy stayed with her
husband's parents in Lake Oswego until Herman brought the family to
Salem, where he worked briefly as a traveling salesman for the
Skidmore Drug Company. Within a year of Lucile's birth in 1904, Herman
Pauling moved his family to Oswego, where he opened his own
drugstore.[18] He moved his family to
Condon, OregonCondon, Oregon in 1905.[19] By
1906, Herman Pauling was suffering from recurrent abdominal pain. He
died of a perforated ulcer on June 11, 1910, leaving Lucy to care for
Linus, Lucile and Pauline.[20]
Pauling attributes his interest in becoming a chemist to being amazed
by experiments conducted by a friend, Lloyd A. Jeffress, who had a
small chemistry lab kit.[21] He later wrote: "I was simply entranced
by chemical phenomena, by the reactions in which substances, often
with strikingly different properties, appear; and I hoped to learn
more and more about this aspect of the world."[22]
In high school, Pauling conducted chemistry experiments by scavenging
equipment and material from an abandoned steel plant. With an older
friend, Lloyd Simon, Pauling set up Palmon Laboratories in Simon's
basement. They approached local dairies offering to perform butterfat
samplings at cheap prices but dairymen were wary of trusting two boys
with the task, and the business ended in failure.[23]
At age 15, the high school senior had enough credits to enter Oregon
State University (OSU), known then as Oregon Agricultural College.[24]
Lacking two American history courses required for his high school
diploma, Pauling asked the school principal if he could take the
courses concurrently during the spring semester. Denied, he left
Washington High School in June without a diploma.[25] The school
awarded him an honorary diploma 45 years later, after he was awarded
two Nobel Prizes.[12][26][27]
Pauling held a number of jobs to earn money for his future college
expenses, including working part-time at a grocery store for $8 per
week. His mother arranged an interview with the owner of a number of
manufacturing plants in Portland, Mr. Schwietzerhoff, who hired him as
an apprentice machinist at a salary of $40 per month. This was soon
raised to $50 per month.[28] Pauling also set up a photography
laboratory with two friends.[29] In September 1917, Pauling was
finally admitted by Oregon State University. He immediately resigned
from the machinist's job and informed his mother, who saw no point in
a university education, of his plans.[30]
Higher education[edit]

Pauling's graduation photo from Oregon State University, 1922

In his first semester, Pauling registered for two courses in
chemistry, two in mathematics, mechanical drawing, introduction to
mining and use of explosives, modern English prose, gymnastics and
military drill.[31] He was active in campus life and founded the
school's chapter of the
Delta UpsilonDelta Upsilon fraternity.[32] After his second
year, he planned to take a job in Portland to help support his mother.
The college offered him a position teaching quantitative analysis, a
course he had just finished taking himself. He worked forty hours a
week in the laboratory and classroom and earned $100 a month, enabling
him to continue his studies.[33]
In his last two years at school, Pauling became aware of the work of
Gilbert N. LewisGilbert N. Lewis and
Irving LangmuirIrving Langmuir on the electronic structure of
atoms and their bonding to form molecules.[33] He decided to focus his
research on how the physical and chemical properties of substances are
related to the structure of the atoms of which they are composed,
becoming one of the founders of the new science of quantum chemistry.
Engineering professor Samuel Graf selected Pauling to be his teaching
assistant in a mechanics and materials course.[34][35][36] During the
winter of his senior year, Pauling taught a chemistry course for home
economics majors. It was in one of these classes that Pauling met his
future wife, Ava Helen Miller.[35]:41[37][38][39]
In 1922, Pauling graduated from Oregon State University[4] (known then
as Oregon Agricultural College) with a degree in chemical engineering.
He went on to graduate school at the California Institute of
Technology (Caltech) in Pasadena, California, under the guidance of
Roscoe Dickinson and Richard Tolman.[1] His graduate research involved
the use of
X-ray diffractionX-ray diffraction to determine the structure of crystals.
He published seven papers on the crystal structure of minerals while
he was at Caltech. He received his PhD in physical chemistry and
mathematical physics,[3] summa cum laude, in 1925.[40]
Personal life[edit]

The Pauling children at a gathering in celebration of the 1954 Nobel
Prizes in Stockholm, Sweden. Seated from left: Linus Pauling, Jr.,
Peter Pauling and Linda Pauling. Standing from left: an unidentified
individual and Crellin Pauling

Pauling married Ava Helen Miller on June 17, 1923. The marriage lasted
until Ava Pauling's death in 1981. They had four children.[41] Linus
Carl Jr. (born 1925) became a psychiatrist; Peter Jeffress
(1931–2003) a crystallographer; Edward Crellin (1937–1997) a
biologist; and Linda Helen (born 1932) married noted
CaltechCaltech geologist
and glaciologist Barclay Kamb.[42]
Pauling was raised as a member of the
LutheranLutheran Church,[43] but later
joined the
Unitarian UniversalistUnitarian Universalist Church.[44] Two years before his
death, in a published dialogue with Buddhist philosopher Daisaku
Ikeda, Pauling publicly declared his atheism.[45]
Pauling died of prostate cancer on August 19, 1994, at 19:20 at home
in Big Sur, California. He was 93 years old.[46] A grave marker for
Pauling was placed in Oswego Pioneer Cemetery in Lake Oswego, Oregon
by his sister Pauline,[47][48] but Pauling’s ashes, along with those
of his wife, were not buried there until 2005.[47]
Career[edit]
In 1926 Pauling was awarded a
Guggenheim Fellowship to travel to
Europe, to study under German physicist
Arnold SommerfeldArnold Sommerfeld in Munich,
Danish physicist
Niels BohrNiels Bohr in Copenhagen and Austrian physicist Erwin
Schrödinger in Zürich. All three were experts in the new field of
quantum mechanics and other branches of physics.[2] Pauling became
interested in how quantum mechanics might be applied in his chosen
field of interest, the electronic structure of atoms and molecules. In
Zürich, Pauling was also exposed to one of the first quantum
mechanical analyses of bonding in the hydrogen molecule, done by
Walter HeitlerWalter Heitler and Fritz London.[49] Pauling devoted the two years of
his European trip to this work and decided to make it the focus of his
future research. He became one of the first scientists in the field of
quantum chemistry and a pioneer in the application of quantum theory
to the structure of molecules.[50]
In 1927, Pauling took a new position as an assistant professor at
CaltechCaltech in theoretical chemistry.[51] He launched his faculty career
with a very productive five years, continuing with his
X-rayX-ray crystal
studies and also performing quantum mechanical calculations on atoms
and molecules. He published approximately fifty papers in those five
years, and created the five rules now known as Pauling's
rules.[52][53] By 1929, he was promoted to associate professor, and by
1930, to full professor.[51] In 1931, the American Chemical Society
awarded Pauling the Langmuir Prize for the most significant work in
pure science by a person 30 years of age or younger.[54] The following
year, Pauling published what he regarded as his most important paper,
in which he first laid out the concept of hybridization of atomic
orbitals and analyzed the tetravalency of the carbon atom.[55]
At Caltech, Pauling struck up a close friendship with theoretical
physicist Robert Oppenheimer, who spent part of his research and
teaching schedule away from U.C. Berkeley at
CaltechCaltech every
year.[56][57] Pauling was also affiliated to UC Berkeley as Visiting
Lecturer in Physics and Chemistry from 1929–1934.[58] Oppenheimer
even gave Pauling a stunning personal collection of minerals.[59] The
two men planned to mount a joint attack on the nature of the chemical
bond: apparently Oppenheimer would supply the mathematics and Pauling
would interpret the results. Their relationship soured when
Oppenheimer tried to pursue Pauling's wife, Ava Helen. When Pauling
was at work, Oppenheimer came to their home and blurted out an
invitation to Ava Helen to join him on a tryst in Mexico. She flatly
refused, and reported the incident to Pauling. He immediately cut off
his relationship with Oppenheimer.[56]:152[57]
In the summer of 1930, Pauling made another European trip, during
which he learned about gas-phase electron diffraction from Herman
Francis Mark. After returning, he built an electron diffraction
instrument at
CaltechCaltech with a student of his, Lawrence Olin Brockway,
and used it to study the molecular structure of a large number of
chemical substances.[60]
Pauling introduced the concept of electronegativity in 1932.[61] Using
the various properties of molecules, such as the energy required to
break bonds and the dipole moments of molecules, he established a
scale and an associated numerical value for most of the elements –
the Pauling
ElectronegativityElectronegativity Scale – which is useful in predicting
the nature of bonds between atoms in molecules.[62]
In 1936, Pauling was promoted to Chairman of the Division of Chemistry
and Chemical Engineering at Caltech, and to the position of Director
of the Gates and Crellin laboratories of Chemistry. He would hold both
positions until 1958.[51] Pauling also spent a year in 1948 at the
University of OxfordUniversity of Oxford as George Eastman Visiting Professor and Fellow
of Balliol.[63]
Nature of the chemical bond[edit]
In the late 1920s, Pauling began publishing papers on the nature of
the chemical bond. Between 1937 and 1938 he took a position as George
Fischer Baker Non-Resident Lecturer in Chemistry at Cornell
University. While at Cornell, he delivered a series of nineteen
lectures[64] and completed the bulk of his famous textbook The Nature
of the Chemical Bond.[65][66]:Preface While at Cornell, Pauling
resided at the Telluride House.[53]:xii It is based primarily on his
work in this area that he received the
Nobel Prize in ChemistryNobel Prize in Chemistry in
1954 "for his research into the nature of the chemical bond and its
application to the elucidation of the structure of complex
substances".[12] Pauling's book has been considered "chemistry's most
influential book of this century and its effective bible".[67] In the
30 years after its first edition was published in 1939, the book was
cited more than 16,000 times. Even today, many modern scientific
papers and articles in important journals cite this work, more than
seventy years after the first publication.[68]
Part of Pauling's work on the nature of the chemical bond led to his
introduction of the concept of orbital hybridization.[69] While it is
normal to think of the electrons in an atom as being described by
orbitals of types such as s and p, it turns out that in describing the
bonding in molecules, it is better to construct functions that partake
of some of the properties of each. Thus the one 2s and three 2p
orbitals in a carbon atom can be (mathematically) 'mixed' or combined
to make four equivalent orbitals (called sp3 hybrid orbitals), which
would be the appropriate orbitals to describe carbon compounds such as
methane, or the 2s orbital may be combined with two of the 2p orbitals
to make three equivalent orbitals (called sp2 hybrid orbitals), with
the remaining 2p orbital unhybridized, which would be the appropriate
orbitals to describe certain unsaturated carbon compounds such as
ethylene.[66]:111–120 Other hybridization schemes are also found in
other types of molecules.
Another area which he explored was the relationship between ionic
bonding, where electrons are transferred between atoms, and covalent
bonding, where electrons are shared between atoms on an equal basis.
Pauling showed that these were merely extremes, and that for most
actual cases of bonding, the quantum-mechanical wave function for a
polar molecule AB is a combination of wave functions for covalent and
ionic molecules.[53]:66 Here Pauling's electronegativity concept is
particularly useful; the electronegativity difference between a pair
of atoms will be the surest predictor of the degree of ionicity of the
bond.[70]
The third of the topics that Pauling attacked under the overall
heading of "the nature of the chemical bond" was the accounting of the
structure of aromatic hydrocarbons, particularly the prototype,
benzene.[71] The best description of benzene had been made by the
German chemist Friedrich Kekulé. He had treated it as a rapid
interconversion between two structures, each with alternating single
and double bonds, but with the double bonds of one structure in the
locations where the single bonds were in the other. Pauling showed
that a proper description based on quantum mechanics was an
intermediate structure which was a blend of each. The structure was a
superposition of structures rather than a rapid interconversion
between them. The name "resonance" was later applied to this
phenomenon.[72] In a sense, this phenomenon resembles those of
hybridization and also polar bonding, both described above, because
all three phenomena involve combining more than one electronic
structure to achieve an intermediate result.
Ionic crystal structures[edit]
In 1929 he published five rules which help to predict and explain
crystal structures of ionic compounds.[73][53] These rules concern (1)
the ratio of cation radius to anion radius, (2) the electrostatic bond
strength, (3) the sharing of polyhedron corners, edges and faces, (4)
crystals containing different cations, and (5) the rule of parsimony.
Biological molecules[edit]

In the mid-1930s, Pauling, strongly influenced by the biologically
oriented funding priorities of the Rockefeller Foundation's Warren
Weaver, decided to strike out into new areas of interest.[74] Although
Pauling's early interest had focused almost exclusively on inorganic
molecular structures, he had occasionally thought about molecules of
biological importance, in part because of Caltech's growing strength
in biology. Pauling interacted with such great biologists as Thomas
Hunt Morgan, Theodosius Dobzhanski,
Calvin Bridges and Alfred
Sturtevant.[75] His early work in this area included studies of the
structure of hemoglobin with his student Charles D. Coryell. He
demonstrated that the hemoglobin molecule changes structure when it
gains or loses an oxygen atom.[75] As a result of this observation, he
decided to conduct a more thorough study of protein structure in
general. He returned to his earlier use of
X-ray diffractionX-ray diffraction analysis.
But protein structures were far less amenable to this technique than
the crystalline minerals of his former work. The best
X-rayX-ray pictures
of proteins in the 1930s had been made by the British crystallographer
William Astbury, but when Pauling tried, in 1937, to account for
Astbury's observations quantum mechanically, he could not.[76]
It took eleven years for Pauling to explain the problem: his
mathematical analysis was correct, but Astbury's pictures were taken
in such a way that the protein molecules were tilted from their
expected positions. Pauling had formulated a model for the structure
of hemoglobin in which atoms were arranged in a helical pattern, and
applied this idea to proteins in general.
In 1951, based on the structures of amino acids and peptides and the
planar nature of the peptide bond, Pauling,
Robert Corey and Herman
Branson correctly proposed the alpha helix and beta sheet as the
primary structural motifs in protein secondary structure.[77][78] This
work exemplified Pauling's ability to think unconventionally; central
to the structure was the unorthodox assumption that one turn of the
helix may well contain a non-integer number of amino acid residues;
for the alpha helix it is 3.7 amino acid residues per turn.
Pauling then proposed that deoxyribonucleic acid (DNA) was a triple
helix;[79][80] his model contained several basic mistakes, including a
proposal of neutral phosphate groups, an idea that conflicted with the
acidity of DNA. Sir Lawrence Bragg had been disappointed that Pauling
had won the race to find the alpha helix structure of proteins.
Bragg's team had made a fundamental error in making their models of
protein by not recognizing the planar nature of the peptide bond. When
it was learned at the
Cavendish LaboratoryCavendish Laboratory that Pauling was working on
molecular models of the structure of DNA,
James WatsonJames Watson and Francis
Crick were allowed to make a molecular model of DNA. They later
benefited from unpublished data from
Maurice WilkinsMaurice Wilkins and Rosalind
Franklin at King's College which showed evidence for a helix and
planar base stacking along the helix axis. Early in 1953 Watson and
Crick proposed a correct structure for the DNA double helix. Pauling
later cited several reasons to explain how he had been misled about
the structure of DNA, among them misleading density data and the lack
of high quality
X-ray diffractionX-ray diffraction photographs. During the time Pauling
was researching the problem,
Rosalind FranklinRosalind Franklin in England was creating
the world's best images. They were key to Watson's and Crick's
success. Pauling did not see them before devising his mistaken DNA
structure, although his assistant
Robert Corey did see at least some
of them, while taking Pauling's place at a summer 1952 protein
conference in England. Pauling had been prevented from attending
because his passport was withheld by the State Department on suspicion
that he had Communist sympathies. This led to the legend that Pauling
missed the structure of DNA because of the politics of the day (this
was at the start of the McCarthy period in the United States).
Politics did not play a critical role. Not only did Corey see the
images at the time, but Pauling himself regained his passport within a
few weeks and toured English laboratories well before writing his DNA
paper. He had ample opportunity to visit Franklin's lab and see her
work, but chose not to.[56]:414–415
Pauling also studied enzyme reactions and was among the first to point
out that enzymes bring about reactions by stabilizing the transition
state of the reaction, a view which is central to understanding their
mechanism of action.[81] He was also among the first scientists to
postulate that the binding of antibodies to antigens would be due to a
complementarity between their structures.[82] Along the same lines,
with the physicist turned biologist Max Delbrück, he wrote an early
paper arguing that
DNA replicationDNA replication was likely to be due to
complementarity, rather than similarity, as suggested by a few
researchers. This was made clear in the model of the structure of DNA
that Watson and Crick discovered.[83]
Molecular genetics[edit]
In November 1949, Pauling, Harvey Itano,
S. J. Singer and Ibert Wells
published "Sickle Cell Anemia, a Molecular Disease"[84] in the journal
Science. It was the first proof of a human disease caused by an
abnormal protein, and sickle cell anemia became the first disease
understood at the molecular level. Using electrophoresis, they
demonstrated that individuals with sickle cell disease have a modified
form of hemoglobin in their red blood cells, and that individuals with
sickle cell trait have both the normal and abnormal forms of
hemoglobin. This was the first demonstration causally linking an
abnormal protein to a disease, and also the first demonstration that
Mendelian inheritanceMendelian inheritance determines the specific physical properties of
proteins, not simply their presence or absence – the dawn of
molecular genetics.[85]
His success with sickle cell anemia led Pauling to speculate that a
number of other diseases, including mental illnesses such as
schizophrenia, might result from flawed genetics. As chairman of the
Division of Chemistry and Chemical Engineering and director of the
Gates and Crellin Chemical Laboratories, he encouraged the hiring of
researchers with a chemical-biomedical approach to mental illness, a
direction not always popular with established
CaltechCaltech chemists.[86]:2
In 1951, Pauling gave a lecture entitled "Molecular Medicine".[87] In
the late 1950s, Pauling studied the role of enzymes in brain function,
believing that mental illness may be partly caused by enzyme
dysfunction.
Structure of the atomic nucleus[edit]
On September 16, 1952, Pauling opened a new research notebook with the
words "I have decided to attack the problem of the structure of
nuclei." On October 15, 1965, Pauling published his Close-Packed
Spheron Model of the atomic nucleus in two well respected journals,
Science and the Proceedings of the National Academy of
Sciences.[88][89][90] For nearly three decades, until his death in
1994, Pauling published numerous papers on his spheron cluster
model.[91][92][93][94][95][96]
The basic idea behind Pauling's spheron model is that a nucleus can be
viewed as a set of "clusters of nucleons". The basic nucleon clusters
include the deuteron [np], helion [pnp], and triton [npn]. Even–even
nuclei are described as being composed of clusters of alpha particles,
as has often been done for light nuclei.[97] Pauling attempted to
derive the shell structure of nuclei from pure geometrical
considerations related to
Platonic solidsPlatonic solids rather than starting from an
independent particle model as in the usual shell model. In an
interview given in 1990 Pauling commented on his model:[98]

Now recently, I have been trying to determine detailed structures of
atomic nuclei by analyzing the ground state and excited state
vibrational bends, as observed experimentally. From reading the
physics literature, Physical Review Letters and other journals, I know
that many physicists are interested in atomic nuclei, but none of
them, so far as I have been able to discover, has been attacking the
problem in the same way that I attack it. So I just move along at my
own speed, making calculations...

Activism[edit]
Wartime work[edit]
Pauling had been practically apolitical until World War II. At the
beginning of the Manhattan Project,
Robert OppenheimerRobert Oppenheimer invited him to
be in charge of the Chemistry division of the project. However, he
declined, not wanting to uproot his family.[99]
Pauling did, however, work on research for the military. He was a
principal investigator on 14 OSRD contracts.[100] The National Defense
Research Committee called a meeting on October 3, 1940, wanting an
instrument that could reliably measure oxygen content in a mixture of
gases, so that they could measure oxygen conditions in submarines and
airplanes. In response Pauling designed the Pauling oxygen meter,
which was developed and manufactured by Arnold O. Beckman, Inc.. After
the war, Beckman adapted the oxygen analyzers for use in incubators
for premature babies.[101]:180–186[102]
In 1942, Pauling successfully submitted a proposal on "The Chemical
Treatment of
ProteinProtein Solutions in the Attempt to Find a Substitute for
Human Serum for Transfusions". His project group, which included J.B.
Koepfli and Dan Campbell, developed a possible replacement for human
blood plasma in transfusions: polyoxy gelatin
(Oxypolygelatin).[103][104]
Other wartime projects with more direct military applications included
work on explosives, rocket propellants and the patent for an
armor-piercing shell. In October 1948 Pauling was awarded a
Presidential Medal for MeritPresidential Medal for Merit by President Harry S. Truman. The
citation credits him for his "imaginative mind", "brilliant success",
and "exceptionally meritorious conduct in the performance of
outstanding services.[105][106][107] In 1949, he served as president
of the American Chemical Society.[108]
Nuclear activism[edit]
The aftermath of the
Manhattan ProjectManhattan Project and his wife Ava's pacifism
changed Pauling's life profoundly, and he became a peace activist. In
1946, he joined the Emergency Committee of Atomic Scientists, chaired
by Albert Einstein.[109] Its mission was to warn the public of the
dangers associated with the development of nuclear weapons.
His political activism prompted the U.S. State Department to deny him
a passport in 1952, when he was invited to speak at a scientific
conference in London.[110][111] In a speech before the
US SenateUS Senate on
June 6 of the same year, Senator
Wayne MorseWayne Morse publicly denounced the
action of the State Department, and urged the Passport Division to
reverse its decision. Pauling and his wife Ava were then issued a
“limited passport” to attend the aforementioned conference in
England.[112][113] His full passport was restored in 1954, shortly
before the ceremony in
StockholmStockholm where he received his first Nobel
Prize.
Joining Einstein,
Bertrand RussellBertrand Russell and eight other leading scientists
and intellectuals, he signed the
Russell-Einstein Manifesto issued
July 9, 1955.[114] He also supported the
Mainau DeclarationMainau Declaration of July
15, 1955, signed by 52 Nobel Prize laureates.[115]
In May 1957, working with
Washington University in St. LouisWashington University in St. Louis professor
Barry Commoner, Pauling began to circulate a petition among scientists
to stop nuclear testing.[116] On January 15, 1958, Pauling and his
wife presented a petition to
United NationsUnited Nations Secretary General Dag
Hammarskjöld calling for an end to the testing of nuclear weapons. It
was signed by 11,021 scientists representing fifty
countries.[117][118]
In February 1958, Pauling participated in a publicly televised debate
with the atomic physicist
Edward TellerEdward Teller about the actual probability
of fallout causing mutations.[119] Later in 1958, Pauling published No
more war!, in which he not only called for an end to the testing of
nuclear weapons but also an end to war itself. He proposed that a
World Peace Research Organization be set up as part of the United
Nations to "attack the problem of preserving the peace".[12]
Pauling also supported the work of the St. Louis Citizen's Committee
for Nuclear Information (CNI).[116] This group, headed by Barry
Commoner, Eric Reiss, M. W. Friedlander and John Fowler, organized a
longtudinal study to measure radioactive strontium-90 in the baby
teeth of children across North America. The "Baby Tooth Survey,"
published by Dr. Louise Reiss, demonstrated conclusively in 1961 that
above-ground nuclear testing posed significant public health risks in
the form of radioactive fallout spread primarily via milk from cows
that had ingested contaminated grass.[120][121][122] The Committee for
Nuclear Information is frequently credited for its significant
contribution to supporting the test ban,[123] as is the
ground-breaking research conducted by Dr. Reiss and the "Baby Tooth
Survey".[124]
Public pressure and the frightening results of the CNI research
subsequently led to a moratorium on above-ground nuclear weapons
testing, followed by the Partial Test Ban Treaty, signed in 1963 by
John F. KennedyJohn F. Kennedy and Nikita Khrushchev. On the day that the treaty went
into force, October 10, 1963, the Nobel Prize Committee awarded
Pauling the
Nobel Peace PrizeNobel Peace Prize for 1962. (No prize had previously been
awarded for that year.)[125] They described him as "Linus Carl
Pauling, who ever since 1946 has campaigned ceaselessly, not only
against nuclear weapons tests, not only against the spread of these
armaments, not only against their very use, but against all warfare as
a means of solving international conflicts."[126] Pauling himself
acknowledged his wife Ava's deep involvement in peace work, and
regretted that she was not awarded the
Nobel Peace PrizeNobel Peace Prize with
him.[127]
Political criticism[edit]
Many of Pauling's critics, including scientists who appreciated the
contributions that he had made in chemistry, disagreed with his
political positions and saw him as a naïve spokesman for Soviet
communism. In 1960 he was ordered to appear before the Senate Internal
Security Subcommittee,[128] which termed him "the number one
scientific name in virtually every major activity of the Communist
peace offensive in this country."[129] A headline in Life magazine
characterized his 1962 Nobel Prize as "A Weird Insult from
Norway".[130]
Pauling was a frequent target of
The National ReviewThe National Review magazine. In an
article entitled "The Collaborators" in the magazine's July 17, 1962
issue, Pauling was referred to not only as a collaborator, but as a
"fellow traveler" of proponents of Soviet-style communism. In 1965,
Pauling sued the magazine, its publisher William Rusher, and its
editor
William F. Buckley, JrWilliam F. Buckley, Jr for $1 million. He lost both his libel
suits and the 1968 appeal.[131][132][133][134]
His peace activism, his frequent travels, and his enthusiastic
expansion into chemical-biomedical research all aroused opposition at
Caltech. In 1958, the
CaltechCaltech Board of Trustees demanded that Pauling
step down as chairman of the Chemistry and Chemical Engineering
Division.[86]:2 Although he had retained tenure as a full professor,
Pauling chose to resign from
CaltechCaltech after he received the Nobel peace
prize money. He spent the next three years at the Center for the Study
of Democratic Institutions (1963–1967).[22] In 1967 he moved to the
University of California at San Diego, but remained there only
briefly, leaving in 1969 in part because of political tensions with
the Reagan-era board of regents.[86]:3 From 1969 to 1974 he accepted a
position as Professor of Chemistry at Stanford University.[51]
Vietnam war activism[edit]
During the 1960s, President Lyndon Johnson’s policy of increasing
America’s involvement in the Vietnam War caused an anti-war movement
that the Paulings joined with enthusiasm. Pauling denounced the war as
unnecessary and unconstitutional. He made speeches, signed protest
letters and communicated personally with the North Vietnamese leader,
Ho Chi Minh, and gave the lengthy written response to President
Johnson. His efforts were ignored by the American government.[135]
Pauling was awarded the International
Lenin Peace PrizeLenin Peace Prize by the USSR in
1970.[129][136] He continued his peace activism in the following
years. He and his wife Ava helped to found the International League of
Humanists in 1974.[137] He was president of the scientific advisory
board of the
World Union for Protection of LifeWorld Union for Protection of Life and also one of the
signatories of the Dubrovnik-Philadelphia Statement of 1974/1976.[138]
Linus Carl Pauling was an honorary president and member of the
International Academy of Science, Munich until the end of his
life.[139]
Eugenics[edit]
Pauling supported a limited form of eugenics by suggesting that human
carriers of defective genes be given a compulsory visible mark - such
as a forehead tattoo - to discourage potential mates with the same
defect, in order to reduce the number of babies with diseases such as
sickle cell anemia.[140][141]
Medical research and vitamin C advocacy[edit]

Pauling's book, How to Live Longer and Feel Better, advocated the very
high intake of Vitamin C.[142]

In 1941, at age 40, Pauling was diagnosed with Bright's disease, a
renal disease. Following the recommendations of Thomas Addis, who
actively recruited
Ava Helen PaulingAva Helen Pauling as "nutritionist, cook, and
eventually as deputy 'doctor'", Pauling was able to control the
disease with Addis's then-unusual low-protein salt-free diet and
vitamin supplements.[143] Thus Pauling's initial – and intensely
personal – exposure to the idea of treating disease with vitamin
supplements was positive.
In 1965 Pauling read
NiacinNiacin Therapy in
PsychiatryPsychiatry by
Abram Hoffer and
theorized vitamins might have important biochemical effects unrelated
to their prevention of associated deficiency diseases.[144] In 1968
Pauling published a brief paper in Science entitled "Orthomolecular
psychiatry",[145] giving a name to the popular but controversial
megavitamin therapy movement of the 1970s, and advocating that
"orthomolecular therapy, the provision for the individual person of
the optimum concentrations of important normal constituents of the
brain, may be the preferred treatment for many mentally ill patients."
Pauling coined the term "orthomolecular" to refer to the practice of
varying the concentration of substances normally present in the body
to prevent and treat disease. His ideas formed the basis of
orthomolecular medicine, which is not generally practiced by
conventional medical professionals and has been strongly
criticized.[146][147]
In 1973, with
Arthur B. RobinsonArthur B. Robinson and another colleague, Pauling
founded the Institute of Orthomolecular Medicine in Menlo Park,
California, which was soon renamed the
Linus Pauling Institute of
Science and Medicine. Pauling directed research on vitamin C, but also
continued his theoretical work in chemistry and physics until his
death. In his last years, he became especially interested in the
possible role of vitamin C in preventing atherosclerosis and published
three case reports on the use of lysine and vitamin C to relieve
angina pectoris. During the 1990s Pauling put forward a comprehensive
plan for the treatment of heart disease using lysine and vitamin C. In
1996 a website was created expounding Pauling's treatment which it
referred to as Pauling Therapy. Proponents of Pauling Therapy believe
that heart disease can be treated and even cured using only lysine and
Vitamin CVitamin C and without drugs or heart operations.[148]
Pauling's work on vitamin C in his later years generated much
controversy. He was first introduced to the concept of high-dose
vitamin C by biochemist
Irwin Stone in 1966. After becoming convinced
of its worth, Pauling took 3 grams of vitamin C every day to
prevent colds.[4] Excited by his own perceived results, he researched
the clinical literature and published
Vitamin CVitamin C and the Common Cold in
1970. He began a long clinical collaboration with the British cancer
surgeon Ewan Cameron in 1971 on the use of intravenous and oral
vitamin C as cancer therapy for terminal patients.[149] Cameron and
Pauling wrote many technical papers and a popular book, Cancer and
Vitamin C, that discussed their observations. Pauling made vitamin C
popular with the public[150] and eventually published two studies of a
group of 100 allegedly terminal patients that claimed vitamin C
increased survival by as much as four times compared to untreated
patients.[151][152]
A re-evaluation of the claims in 1982 found that the patient groups
were not actually comparable, with the vitamin C group being less sick
on entry to the study, and judged to be "terminal" much earlier than
the comparison group.[153] Later clinical trials conducted by the Mayo
Clinic also concluded that high-dose (10,000 mg) vitamin C was no
better than placebo at treating cancer and that there was no benefit
to high-dose vitamin C.[154][155][156] The failure of the clinical
trials to demonstrate any benefit resulted in the conclusion that
vitamin C was not effective in treating cancer; the medical
establishment concluded that his claims that vitamin C could prevent
colds or treat cancer were quackery.[4][157] Pauling denounced the
conclusions of these studies and handling of the final study as "fraud
and deliberate misrepresentation",[158][159] and criticized the
studies for using oral, rather than intravenous vitamin C[160] (which
was the dosing method used for the first ten days of Pauling's
original study[157]). Pauling also criticised the Mayo clinic studies
because the controls were taking vitamin C during the trial, and
because the duration of the treatment with vitamin C was short;
Pauling advocated continued high-dose vitamin C for the rest of the
cancer patient's life whereas the Mayo clinic patients in the second
trial were treated with vitamin C for a median of 2.5 months.[161] The
results were publicly debated at length with considerable acrimony
between Pauling and Cameron, and Moertel (the lead author of the Mayo
Clinic studies), with accusations of misconduct and scientific
incompetence on both sides.
Ultimately the negative findings of the
Mayo ClinicMayo Clinic studies ended
general interest in vitamin C as a treatment for cancer.[159] Despite
this, Pauling continued to promote vitamin C for treating cancer and
the common cold, working with The Institutes for the Achievement of
Human Potential to use vitamin C in the treatment of brain-injured
children.[162] He later collaborated with the Canadian physician Abram
Hoffer on a micronutrient regime, including high-dose vitamin C, as
adjunctive cancer therapy.[163] A 2009 review also noted differences
between the studies, such as the Mayo clinic not using intravenous
Vitamin C, and suggested further studies into the role of vitamin C
when given intravenously.[164] Results from most clinical trials
suggest that modest vitamin C supplementation alone or with other
nutrients offers no benefit in the prevention of cancer.[165][166]
Legacy[edit]
Pauling's discoveries led to decisive contributions in a diverse array
of areas including around 350 publications in the fields of quantum
mechanics, inorganic chemistry, organic chemistry, protein structure,
molecular biology, and medicine.[167][168]
His work on chemical bonding marks him as one of the founders of
modern quantum chemistry.[8] The Nature of the Chemical Bond was the
standard work for many years,[169] and concepts like hybridization and
electronegativity remain part of standard chemistry textbooks. While
his
Valence bondValence bond approach fell short of accounting quantitatively for
some of the characteristics of molecules, such as the color of
organometallic complexes, and would later be eclipsed by the molecular
orbital theory of Robert Mulliken, Valence Bond Theory still competes,
in its modern form, with Molecular Orbital Theory and density
functional theory (DFT) as a way of describing the chemical
phenomena.[170] Pauling's work on crystal structure contributed
significantly to the prediction and elucidation of the structures of
complex minerals and compounds.[35]:80–81 His discovery of the alpha
helix and beta sheet is a fundamental foundation for the study of
protein structure.[78]
Francis CrickFrancis Crick acknowledged Pauling as the "father of molecular
biology".[8][171] His discovery of sickle cell anemia as a "molecular
disease" opened the way toward examining genetically acquired
mutations at a molecular level.[85]
Pauling’s 1951 publication with Robert B. Corey and H. R. Branson,
“The Structure of Proteins: Two Hydrogen-Bonded Helical
Configurations of the Polypeptide Chain,” was a key early finding in
the then newly emerging field of molecular biology. This publication
was honored by a Citation for Chemical Breakthrough Award from the
Division of History of Chemistry of the American Chemical Society
presented to the Department of Chemistry, Caltech, in 2017.[172][173]
Commemorations[edit]
The Pauling Centre for Human Sciences at the
University of OxfordUniversity of Oxford was
named after
Linus PaulingLinus Pauling in honour of his contribution across both
the sciences and humanities.
Oregon State UniversityOregon State University completed construction of the $77 million,
100,000 square foot
Linus PaulingLinus Pauling Science Center in the late 2000s,
now housing a bulk of Oregon State's chemistry classrooms, labs, and
instruments.[174]
On March 6, 2008, the
United States Postal ServiceUnited States Postal Service released a 41 cent
stamp honoring Pauling designed by artist Victor Stabin.[175][176] His
description reads: "A remarkably versatile scientist, structural
chemist
Linus PaulingLinus Pauling (1901–1994) won the 1954 Nobel Prize in
Chemistry for determining the nature of the chemical bond linking
atoms into molecules. His work in establishing the field of molecular
biology; his studies of hemoglobin led to the classification of sickle
cell anemia as a molecular disease."[85] The other scientists on this
sheet of stamps included Gerty Cori, biochemist, Edwin Hubble,
astronomer, and John Bardeen, physicist.[176]
California Governor
Arnold SchwarzeneggerArnold Schwarzenegger and First Lady Maria Shriver
announced on May 28, 2008 that Pauling would be inducted into the
California Hall of Fame, located at The California Museum for History,
Women and the Arts. The induction ceremony took place December 15,
2008. Pauling's son was asked to accept the honor in his place.[177]
By proclamation of Gov.
John KitzhaberJohn Kitzhaber in the state of Oregon,
February 28 has been named "
Linus PaulingLinus Pauling Day".[178] The Linus Pauling
Institute still exists, but moved in 1996 from Palo Alto, California,
to Corvallis, Oregon, where it is part of the
Linus PaulingLinus Pauling Science
Center at Oregon State University.[179][180][181] The Valley Library
SpecialSpecial Collections at
Oregon State UniversityOregon State University contain the Ava Helen
and
Linus PaulingLinus Pauling Papers, including digitized versions of Pauling's
forty-six research notebooks.[178]
In 1986,
CaltechCaltech commemorated
Linus PaulingLinus Pauling with a Symposia and
Lectureship.[182] The Pauling Lecture series at
CaltechCaltech began in 1989
with a lecture by Pauling himself. The
CaltechCaltech Chemistry Department
renamed room 22 of Gates Hall the
Linus PaulingLinus Pauling Lecture Hall, since
Linus spent so much time there.[183]
Other places named after Pauling include Pauling Street in Foothill
Ranch, California;[184]
Linus PaulingLinus Pauling Drive in Hercules, California;
Linus and
Ava Helen PaulingAva Helen Pauling Hall at
Soka University of AmericaSoka University of America in
Aliso Viejo, California;[185]
Linus PaulingLinus Pauling Middle School in
Corvallis, Oregon;[186] and Pauling Field, a small airfield located in
Condon, Oregon, where Pauling spent his youth.[187] There is a
psychedelic rock band in Houston, Texas, named The Linus Pauling
Quartet.[188]
The asteroid
4674 Pauling in the inner asteroid belt, discovered by
Eleanor F. Helin, was named after
Linus PaulingLinus Pauling in 1991, on his 90th
birthday.[189]
Linus Torvalds, developer of the
LinuxLinux kernel, is named after
Pauling.[190]
Nobel laureate
Peter AgrePeter Agre has said that
Linus PaulingLinus Pauling inspired
him.[191]
Honors and awards[edit]
Pauling received numerous awards and honors during his career,
including the following:[192][51][193]

— Wilson, E. B. (1985) [Originally published in 1935]. Introduction
to Quantum Mechanics with Applications to Chemistry. Reprinted by
Dover Publications. ISBN 0-486-64871-0.
— (1939). The Nature of the Chemical Bond and the Structure of
Molecules and Crystals.
Cornell UniversityCornell University Press.
— (1947). General Chemistry: An Introduction to Descriptive
Chemistry and Modern Chemical Theory. W. H. Freeman.

Greatly revised and expanded in 1947, 1953, and 1970. Reprinted by
Dover Publications in 1988.

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